P0603
P0603 ECM POWER SUPPLY
Component Description
Battery voltage is supplied to the ECM even when the ignition switch is turned OFF for the ECM memory function of the DTC memory, the air-fuel ratio feedback compensation value memory, the idle air volume learning value memory, etc.
On Board Diagnosis Logic
On Board Diagnosis Logic:
DTC Confirmation Procedure
1. If DTC Confirmation Procedure has been previously conducted, always perform the following before conducting the next step.
a. Turn ignition switch OFF and wait at least 10 seconds.
b. Turn ignition switch ON.
c. Turn ignition switch OFF and wait at least 10 seconds.
2. Start engine and let it idle for 1 second.
3. Turn ignition switch OFF, wait at least 10 seconds and then turn ON.
4. Repeat steps 1 and 2 for 4 times.
5. Check 1st trip DTC.
6. If 1st trip DTC is detected, go to P0603.
Diagnosis Procedure
1.CHECK ECM POWER SUPPLY
1. Turn ignition switch OFF.
2. Disconnect ECM harness connector.
3. Check voltage between ECM terminal 121 and ground with
CONSULT-III or tester.
Voltage: Battery voltage
OK or NG
OK - GO TO 3.
NG - GO TO 2.
2.DETECT MALFUNCTIONING PART
Check the following.
- IPDM E/R connector E121
- 20A fuse
- Harness for open or short between ECM and battery
>> Repair or replace harness or connectors.
3.CHECK INTERMITTENT INCIDENT
Refer to How to Check Terminal and Intermittent Incident.
OK or NG
OK - GO TO 4.
NG - Repair or replace harness or connectors.
4.PERFORM DTC CONFIRMATION PROCEDURE
With CONSULT-III
1. Turn ignition switch ON.
2. Select "SELF DIAG RESULTS" mode with CONSULT-III.
3. Touch "ERASE".
4. Perform DTC Confirmation Procedure.
See P0603.
5. Is the 1st trip DTC P0603 displayed again?
With GST
1. Turn ignition switch ON.
2. Select Service $04 with GST.
3. Perform DTC Confirmation Procedure.
See P0603.
4. Is the 1st trip DTC P0603 displayed again?
Yes or No
Yes - GO TO 5.
No >> INSPECTION END
5.REPLACE ECM
1. Replace ECM.
2. Perform initialization of IVIS(NATS) system and registration of all IVIS(NATS) ignition key IDs. Refer to ECM Re-Communicating Function.
3. Perform Testing and Inspection.
4. Perform Testing and Inspection.
5. Perform Throttle Valve Closed Position Learning.
6. Perform Testing and Inspection.
>> INSPECTION END